Image projection apparatus and circuit-board retaining structure

1. An image projection apparatus for projecting an image onto a projection surface, the image projection apparatus comprising: a light source device configured to emit light; a first circuit board including an image display device configured to form an image using the light, a connector, and an electrically conductive portion near the connector; a retaining member made of metal; an optical illuminating unit held by the retaining member and configured to guide the light emitted from the light source device to the image display device; an optical projecting unit configured to project the image formed by the image display device onto the projection surface; a second circuit board configured to be electrically connected to the connector of the first circuit board; a metal plate fixed and electrically connected to the retaining member; and an elastic metal member arranged on the metal plate, wherein the first circuit board is fixed to the retaining member, the elastic metal member is in contact with the electrically conductive portion of the first circuit board, and the second circuit board is fixed and electrically connected to the metal plate.

2. The image projection apparatus according to claim 1 , wherein the electrically conductive portion, with which the elastic metal member is in contact and which is near the connector, includes a plurality of the electrically conductive portions, and at least one of the electrically conductive portions is on a front side of the first circuit board and other one or more of the electrically conductive portions are on a back side of the first circuit board.

3. The image projection apparatus according to claim 1 , wherein the elastic metal member includes a plurality of the elastic metal members, the plurality of the elastic metal members is fixed to the metal plate, and the plurality of elastic metal members is identical to each other in shape.

4. The image projection apparatus according to claim 1 , further comprising a second retaining member independent of the retaining member, wherein an insertion-type input/output terminal having a screw hole is mounted on the second circuit board, the input/output terminal is fixed to the second retaining member with a screw fastened through the screw hole, and the retaining member and the second retaining member are not fixed to each other.

5. A circuit-board retaining structure comprising: a first circuit board including an image display device configured to form an image using light, a connector, and an electrically conductive portion near the connector; a retaining member made of metal; a second circuit board configured to be electrically connected to the connector of the first circuit board; a metal plate fixed and electrically connected to the retaining member; and an elastic metal member arranged on the metal plate, wherein the first circuit board is fixed to the retaining member, the elastic metal member is in contact with the electrically conductive portion of the first circuit board, and the second circuit board is fixed and electrically connected to the metal plate.